jQuery check radio option not checking

Question

I can't get the radio options to check on my page. They won't check Yes or No.

                    for (var i = 0; i < r.length; i++) {
                        jQuery('#condition-'+i+'-price').val(r[i].price);
                        jQuery('#condition-'+i+'-bid').val(r[i].bid);
                        console.log('[value='+r[i].on_amazon+']');
                        console.log(jQuery('#condition-'+r[i].condition_id+'-on_amazon').filter('[value='+r[i].on_amazon+']'));
                        jQuery('#condition-'+r[i].condition_id+'-on_amazon').filter('[value='+r[i].on_amazon+']').attr('checked', true);
                    }

r[i].on_amazon is always 1 or 0 and condition_id is correct because price/bid successfully update...

<tr>
                            <td><label for="on_amazon-1-yes">Yes</label></td>
                            <td class="yes"><input type="radio" id="condition-1-on_amazon" value="1"></td>
                            <td>&nbsp;</td>
                            <td class="no"><input type="radio" id="condition-1-on_amazon" value="0"></td>
                            <td><label for="on_amazon-1-no">No</label></td>
                        </tr>

Answer 1

Set $(radiobtn).attr('checked','checked') instead of true, assuming you're using XHTML.

Answer 2

Try doing:

jQuery('#condition-'+r[i].condition_id+'-on_amazon').filter('[value='+r[i].on_amazon+']')[0].checked=true;